The present invention relates to a noise reduction system provided in a tape reproducing system.
A tape deck is provided with a noise reduction system wherein the level of sounds in middle to high frequency range where tape hiss is most objectionable, is compressed at recording and expanded at reproduction. In the typical noise reduction system such as above, since components of noise differ in accordance with the frequency range thereof, the components of the sound signal is divided into a plurality of frequency bands. A sliding band filter is provided, or the signal components are compressed and expanded so that the ratio of the noise to the signal is increased. The components are thereafter synthesized to obtain the sound signal. Another noise reproduction system uses masking effect caused by the human hearing characteristics. A low level limitter is provided to cancel noises.
In these noise reduction system, the sound signals must be controlled both at recording and at reproduction. In addition, the noise reduction cannot be carried out at the reproduction unless the signals are compressed at the recording.